Sleep disturbances in patients with Alzheimer's disease - Epidemiology, pathophysiology and treatment

Older adults represent an ever-growing proportion of the population of the industrialised nations, with a corresponding increase in the numbers of pat ients with dementing disorders. A common complaint in both normal aging and the dementias. is that of signi ficant sleep disturbance. The major causes of sleep disruption in aging and dementia include: (i) physiological changes that arise as part of normal, 'non-pathological' aging; (ii) sleep problems due to one of many physical o r mental , health conditions and their treatments; (iii) primary sleep diso rders; (iv) poor,sleep hygiene', that is, sleep-related practices and habit s; and (v) some combination of these factors. Disrupted sleep in patients with dementia is a significant cause of stress for caregivers and frequently leads to institutionalisation of patients. It should be a target of clinical management when the goal is sustained home care, and when it is associated with disturbances of mood or behaviour. While the neuropathology of dementia can directly disrupt sleep, sleep dist urbances in patients with dementia often have multiple causes that require systematic evaluation. Thorough assessment of associated psychopathology, d ay-time behaviour, medical disorders, medications, pain and environmental c onditions is needed for optimal management. Differential diagnosis of a sleep problem in dementia is the basis of ratio nal pharmacotherapy. However, patients with dementia are likely to be more sensitive than elderly persons without dementia to adverse cognitive and mo tor effects of drugs prescribed for sleep. Clinicians need to: (i) evaluate sleep outcomes when treating medical, psyc hiatric and behavioural disorders in older adults; (ii) be alert to emergin g behavioural and environmental approaches to treatment; (iii) combine nonp harmacological strategies with drug therapies, when required, for added val ue; and (iv) avoid use of multiple psychotropic medications unless they pro ve essential to the adequate management of sleep disturbances.